Filter elements



.Oct. 13, 1959 K. E. BUCKMAN 2,908,350

- FILTER ELEMENTS Filed Dec. 8, 1954 2 Sheets-Sheet 1 Inventor 15/272655 (5 fizzcfizzm y g 2 Attorney Oct. 13, 1959 K. E. BUCKMAN 2,903,350

FILTER ELEMENTS Filed Dec..8, 1954 2 Sheets-Sheet 2 l 2/ F /G,6 I I m /a /a /e /9 Inventor JlQIZIZKZ /i 5. fizzqivzezz B Attorney United States Patent "ice FILTER ELEMENTS Kenneth Ernest Buckman, Redbridge, Southampton,

England, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application December 8, 1954, Serial No. 473,887

Claims priority, application Great Britain January 30, 1954 1 Claim. (Cl. 183-44) bution engines, they may also be used in the filtration Y of other fluids such as oil.

The object of the invention is to provide a rectangular filter element which may economically be formed and by a simple process; the element being particularly but not exclusively for use in conjunction with an automobile engine.

Another object of the invention is to provide a filter element formed of a continuous web of filter material folded into a stack of superposed sections, at least alternate sections having longitudinal ribs to form a plurality of channels between each pair of adjacent sections, each channel being open at one end only, and the channels on opposite sides of each section being open at opposite ends of the latter.

Longitudinal ribs may be upset in each section of the web, the ribs in alternate sections being offset laterally with respect to those in adjacent sections, the ribs in alternate sections may be offset by half the pitch of the ribs in adjacent sections, and the ribs in adjacent sections may be formed on opposite sides of the web.

Lateral folding spaces or grooves may be formed by cross-grooving adjacent cross grooves being formed on opposite sides of the web and alternate grooves being on one side.

The longitudinal edge portions of the sections may be raised out of the plane of the web and pairs of abutting edges adhesively secured.

Alternatively, the longitudinal edge portions of the sections may be raised up out of the plane of the web and dimpled below the plane of the web at positions spaced from the edges, pairs of abutting edges being secured together by pressure upon the stack.

The scope of the invention is defined by the appended claim; and how it can be carried into effect is hereinafter particularly described with reference to the accompanying drawings in which:

Fig. l is a plan of a web of filter material from which a filter element in accordance with the invention can be made;

Fig. 2 is a longitudinal section through the web of Fig. 1;

Fig. 3 and Fig. 4 are sections on line III-III and lV-IV of Fig. l;

Fig. 5 is a section on line V-V of Fig. 6;

Fig. 6 is an elevation largely in section of a filter embodying a filter element according to the invention;

Fig. 7 is a side elevation, largely in section, of the same filter; and

Patented Oct. 13, 1959 Fig. 8 is a section similar'to Fig. 5 of a modified form of filter element.

As shown in the drawings a single length or web 11 of filter material consists of resin-impregnated paper (Fig. 1'). The Webb 11 is passed through a press which forms longitudinal ribs 1 2. in one section of the web and at the same stroke forms longitudinal ribs 13 in the adjacent section and offset laterally with respect to those in the one section. The web is at the same time crossgrooved to form lateral fold spaces or grooves 14 and 14a between each section, alternate cross grooves being formed on the same side of the web.

In passing through the press the longitudinal edge portions of the sections 15 and 16 are raised out of the plane of the web 11 and edge dimples 17 are also formed. The web 11 is then indexed through the press and the next double section formed. As an alternative to pressing, rollers could be used.

Adhesive is then applied to one side of the longitudinal edge portions 15 and the web 11 is folded in alternate opposite directions, at the lateral folding grooves 14 and 14a to form a stack of superposed sections in zig-zag form (Figs 5 and 7). The abutting margins or edges 15a of the raised longitudinal edge portions are then secured by the adhesive so as to form a filter element with a plurality of channels between sections, each channel being open at one end only and the inlet channels 17a on one side of a section being open at opposite ends to the outlet channels 18 on the other side of a section. The dimples 17 abut as shown in Fig. 5 and the edges 15a of the sections can be sealed by adhesive.

The folded stack is then sealed around one end with a metal flange 19 (Figs. 6 and 7) by which the filter element is then mounted in a metal casing 20 having an outlet 21 to the air inlet of an internal combustion engine and an open inlet 22, covered by a perforated metal sheet 23. The open ends of one set of channels 17a are directed to the inlet 22 of the casing and the open ends of the other set of channels 18 are directed to the outlet 21 of the casing.

In use, air for combustion enters the filter casing 20 at the inlet 22 and passes through the open ends of the channels 17a formed between the ribs of adjacent sections. As each channel 17a is closed at the other end, the air must pass through the paper filter material to reach the outlet channels 18 whose open ends face the outlet 21 of the filter casing 20.

The length of the sections is so chosen that the air which enters through a comparatively small inlet area, passes through a large area of filter material, thus ensuring as small a pressure drop as possible and a long eitective life to the filter.

If the filter is mounted with the inlet facing downwards, the vibration of the engine will effect a cleaning action by shaking out particles from the filter.

In a modification shown in Fig. 8, sections 31 are flat and alternate sections 31a are ribbed but otherwise the construction is similar. The channels 32 with their open ends facing one way, are each formed under a rib by a flat section 31. The channels 33 with their open ends facing the other way, are each formed between two ribs by a flat section 31.

As an alternative to the application of adhesive to the longitudinal edges 15, the web pairs of abutting edges 15a are sealed by pressure upon the stack, the pressure being transferred solely through the dimples 17.

The invention has a primary application to air cleaners on internal combustion engines; and in such application the filter incorporates a silencer chamber (not shown).

I claim:

A filter element comprising an elongated web or filter material transversely folded in a zigzag arrangement of superposed and corrugated sections joined by oppositely disposed folds, each corrugated section having ridges extending along the length of said web normal to said folds and forming channels located between adjacent sections and defined by the ridges of one section contacting the web portion of an adjacent section, two sections of each alternate pair of said sections being sealed together at their opposite margins parallel with said ridges, each of said channels being open at one end of said element and closed at the other end of said element by one of said folds, and the element structure being such that fluid introduced at one end thereof will enter and flow along the channels at one side of said web, pass through the said filter material and discharge along and from the channels at the other side of said web.

References Cited in the file of this patent UNITED STATES PATENTS 1,958,750 Graham May 15, 1934 1,965,172

Cammen July 3, 1934 20 4 Thomas May 4, Perry Nov. 12, Niederauer July 11, Cross Aug. 15, Sigmund Apr. 2, Vokes a? Oct. 29, Horthy Dec. 13, Sapp July 11, Cummings et a1 Nov. 28, Kovacs Sept. 25, Burks et a1. Mar. 4, Ericson Apr. 1, Ericson May 20, Grifliths July 8, Wright et a1. Mar. 3, Ens May 11, Cox et a1 Dec. 6,

FOREIGN PATENTS Australia Mar. 10, 

